Mixed explosive compositions oxygen balance

Most explosive and propellant compositions contain a mixture of components so as to optimize their performance. Some of the components may not contribute to the heat liberated and may not even contain oxygen. These materials may however, contribute to the gaseous products and reduce the actual temperatures obtained on detonation of the explosive or burning of the propellant. An example of a typical mixed explosive composition is one which contains 60% RDX and 40% TNT, and where the heat of explosion Q has been optimized. In order to calculate the values of Q and V for this composition the oxygen balance and the reaction for decomposition need to be determined. But even before these can be calculated the atomic composition of the mixture must first be established. 

The molecules of a composite liquid explosive are fully mixed and evenly dispersed. Thus, its detonation velocity is almost the same as a single compound liquid explosive. It is also not difficult to prepare an explosive with zero oxygen balance to make the utmost out of energy. For example, the explosion heat of hydrazine nitrate and hydrazine composite is up to 6.688 MJ/kg, while the value for octogen (HMX) is only 5.668 MJ/kg. The volume energy for the hydrazine nitrate and hydrazine composite and HMX is 10.62 and 10.5 kJ/cm, respectively, and the maximum detonation velocity is 8,600 m/s ip = 1.33 g/cm ) and 8,900 m/s ip = 1,91 g/cm ), respectively. Hence, liquid explosives have superior explosive property. 

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